A Real-time Needle Tracking Algorithm with First-frame Linear Structure Removing in 2D Ultrasound-guided Prostate Therapy

In ultrasound–guided percutaneous interventions, tracking needle tip is always difficult due to the existence of speckle artifact. Moreover, the complexity of prostate tissue increases the difficulties. In this paper, a real-time needle tracking algorithm is presented for localization and tracking of needle’s tip in 2D ultrasound images during robotic biopsy and brachytherapy. The proposed method uses image without needle as reference to detect needle insertion in an initial step, and this is followed-up with removal of linear structure in surrounding tissue. Validation for needle localization was performed with 827 sequence frames observed in a prostate phantom. While, the shortest detectable needle length observed is 4.50 mm, shaft and tip localization errors are 1.04 ± 0.35 the degree and 0.75 ± 0.6 mm, respectively, and the least tip localization error was 0.06 mm. Meanwhile, a total processing time and single frame average processing time of 33 secs and 40 msec were achieved, respectively. Thus, our algorithm could track the needle tip in an acceptable tracking accuracy and time useful for robotic prostate therapy.